Rail retaining device

ABSTRACT

A rail retaining device has a shoulder member for bearing on a lateral side of a rail flange. The shoulder has a downwardly facing abutment surface. A rail clip is of bent rod symmetrical about a vertical plane. The clip has an inner portion bearing on the flange, intermediate limb portions reacting with the abutment surface and flexed resiliently downwardly in the installed position, and an outer portion connected to each intermediate limb portion and extending arcuately outwardly and downwardly to a lower portion adapted to bear on a bearing surface.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of application PCT/CA99/00966filed Oct. 13, 1999.

BACKGROUND OF THE INVENTION

The present invention relates to rail retaining devices forincorporation in a rail track.

BRIEF SUMMARY OF THE INVENTION

The invention provides a rail retaining device comprising a shouldermember for bearing on a lateral side of a rail flange, and providing adownwardly facing abutment surface, and a rail clip in the form of abent rod symmetrical about a vertical plane for extending laterally ofthe rail and having an inner portion for bearing on an adjacent flangein an installed position, intermediate limb portions for bearingupwardly on the downwardly facing abutment surface, and an outer portionconnected to each intermediate limb portion for extending outwardly fromsaid abutment surface and curving laterally arcuately outwardly anddownwardly toward a lower portion adapted to bear on a bearing surface,and wherein in said installed position there is a reaction between theintermediate limb portions and the downwardly forcing abutment surfaceflexing the intermediate limb portions resiliently downwardly.

The arrangement of the invention provides excellent stress distributionand avoids stress concentrations that can contribute to prematurefailure in known clips. Further, the clip is compliant and tolerant ofdimensional variation in the components and is relatively easily toinstall, while providing a highly effective and durable rail retainingfunction.

Preferably, the lower portion of the clip is adapted to bear on abearing surface at a region that is offset laterally inwardly from acentre of curvature of the outer portion. This further improves thestress distribution through the clip in service.

In a preferred form, the inner portion comprises an upwardly bowedportion adjacent the abutment surface that provides increased resistanceto migration of the clip outwardly from its installed position as aresult of impacts or vibration encountered in service.

Preferably, each lower portion of said outer portions inclineslongitudinally with respect to said vertical plane, whereby squatting ofthe outer portion is facilitated during installation, rendering the clipparticularly compliant and facilitating installation.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Examples are described in more detail hereinafter, by way of example,with reference to the accompanying drawings.

FIGS. 1, 2 and 3 show side, top and isometric views of installed railretaining devices in accordance with a first embodiment of the presentinvention.

FIG. 4 shows an isometric view of the clip employed in the arrangementsof FIGS. 1 to 3.

FIGS. 5, 6, 7 and 8 show top, isometric, side and front views of asecond embodiment of a rail clip in accordance with the invention.

FIG. 9 (which appears on the same sheet as FIG. 4) shows an isometricview of a third embodiment of the rail clip.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings, wherein like reference numerals indicate likeparts, FIGS. 1 to 3 show a fastening arrangement employing a steel tie20, electrically insulating cant plate 50 and hook-in field and gaugeshoulder members 60 and 70, respectively, these elements being generallyas and installed as described in, applicant's published application WO96/23107, which should be referred to for further details and thedisclosure of which is incorporated herein by reference.

While the clips described herein are preferably employed with the abovedescribed shoulder members, it is contemplated they may be used withother shoulder members providing a downwardly facing abutment surface.

In the installed position, as seen in FIGS. 1 to 3, clips 80 extendthrough openings 61 and 71 in the shoulder members 60 and 70,respectively, and bear upwardly on a downwardly facing abutment surfaceprovided on an upper side of the opening 61 or 71, for example onsurface 62 as shown in broken lines in FIG. 1. An end portion 81 of theclip 80, disposed laterally inwardly of the clip 80 with respect to arail 30 bears on a rail flange 31 either directly, or, more usually,through an electrical insulator pad 90 interposed between the railflange 31 on the one hand and the clip 80 and the shoulder 60 or 70 onthe other.

A laterally outer end of the clip 80 engages on a bearing surface, forexample a laterally outer extension 63 or 73 of the shoulder 60 or 70.Preferably, the upper surface of the extensions 63 or 73, as well as thelower side of the opening 61 or 71, inclines upwardly laterally inwardlyto provide an inclining ramp surface facilitating installation byguiding the clip 80 upwardly on to the upper side of the flange 31.

Also visible in FIG. 1 are the hook-in leg portions 64 and 74 formedintegrally with shoulders 60 and 70, respectively, and that are passedthrough openings in the tie 20 and secure the shoulder portions 60 and70, to the tie 20 For details of the arrangement of the hook-in legportions and of the openings in which they are received, referenceshould be made to WO 96/23107 referred to above.

As seen in more detail in FIG. 4, the clip 80 is of bent rod form. Thisbent rod clip 80 has an advantage over similar plate form clips that itis not subject to failure by delamination. The clip 80 is symmetricalabout a vertical plane 82, indicated in FIG. 2, extending laterally ofthe rail 30, with the inner portion 81 for bearing on the rail flange,intermediate limb portions 83 for engaging upwardly on the downwardlyfacing abutment surface such as surface 62, and an outer portion 84curving laterally arcuately outwardly and downwardly and for bearing ona bearing surface such as an upper surface 66 of the extension 62 or 72.

In the installed condition, as seen in FIGS. 1 to 3, the downwardlyfacing abutment surface, for example surface 62, engages theintermediate portions 83 of the clip 80 and the downward reaction withthe surface 62 flexes the portions 83 downwardly with respect to theinner and outer portions 81 and 84. There is therefore correspondingupward reaction at the inner and outer portion 81 and 84. The reactionat the inner portion 81 applies a toe load to the flange 31 while theouter portion 84 tends to flex resulting in compression of the outerportion.

It has been formed that this arrangement results in surprisinglyexcellent stress distribution and avoids stress concentrations thatwould tend to lead to premature failure of the clip. It is believed thatthe stress distribution results from the stress reversals that occurthrough the length of the clip 80. That is to say at the inner and outerportions 81 and 84 there are upward reactions on the clip 80 while inthe intermediate portion 83 there is a downward reaction acting on theclip. The stress distribution is further improved by having the lowerportion of the outer portions 84 bear on the bearing surface 63 along asubstantial part of their length, as best seen in FIG. 1, at a regionthat is offset laterally inwardly from the centre of curvature of theouter portion 84.

In preferred form, the inner portion 81 of the clip 80 includes upwardlybowed portions 86 that reacts with the surface 62 to provide a reactionhaving an inwardly directed component of force on uplift of the railflange 31, so that vertical vibration or oscillation of the flange 31creates forces tending to resist migration of the clip 80 outwardly fromthe shoulder 60 or 70. Desirably, in the non-compressed or free,non-installed condition of the clip 80 as best seen in FIG. 7, a slopingside of the upwardly bowed portion 86 at its side adjacent the surface63, defines with the lower side of the lower portion 107 (or a line Sdrawn tangential to the lowermost portion thereof) a positive angle θ.That is, lines T and S intersect at a point laterally outwardly ofportion at an angle greater than 0° and less than 90°, preferably about10° to 30°, more preferably about 15° to about 25°, and still morepreferably about 20°.

In the preferred form, each lower portion 84, as best seen in FIG. 2inclines longitudinally with respect to the vertical plane 82, so thatduring installation, when the clip 80 is driven inwardly through theopening 61 or 71, the portions 84 can twist sideways relative to theremainder of the clip 80, so that the lower outer portion of the clip 80compresses or squats. This renders the clip 80 particularly compliantand easy to install. In the example illustrated in FIGS. 1 to 4, theportions 84 are toed inwardly. Once installed, the clip 80 of FIGS. 1 to4 resists rail uplift since squatting is limited by the portions 84approaching and touching one is another.

In a preferred form of clip 100, shown in FIGS. 5 to 8 the lowerportions 107 are toed outwardly. This arrangement provides a widerfootprint and greater stability for the clip during installation, andreduces any tendency for the clip to spring outwardly from the shoulderwhen driven inwardly relative to the shoulder. The clip 100 is otherwisesimilar to that described above with reference to FIGS. 1 to 4. Clip 100may be used with shoulders having extensions such as extensions 63,having anti-squat side wall members, such as raised walls 108 as seen inFIG. 3, disposed longitudinally outwardly from lower portions 107. Thewalls 108 limit outward movement of portions 107 and limit the extent ofsquatting when uplift of the flange 31 occurs.

Clip 110 shown in FIG. 9 is similar to clips 100 except extensions oflower portion 84 or end portions 108 extend upwardly and abut the outerside of the shoulder and extend above the upper edge of the shouldersuch as shoulder 60 in the installed position. The exposed upper ends ofthe portion 108 may be engaged by tools to facilitate removal of theclips when desired.

In use the clips 80, 100 and 110 may be installed by laying their innerends 81 loosely in the openings 61 or 71 and driving the clips inwardlywith an inwardly directed force applied to the end of the outer portionsuntil the upwardly bowed portion snaps past downwardly facing abutmentsurface such as surface 62 as the inner end portion 81 rides up theflange 31 or pre-installed insulator 90, and the intermediate portion 83is flexed resiliently downwardly.

What is claimed is:
 1. A rail retaining device comprising a shouldermember for bearing on a lateral side of a rail flange, and providing adownwardly facing abutment surface, and a rail clip in the form of abent rod symmetrical about a vertical plane for extending laterally ofthe rail and having an inner portion for bearing on the rail flange inan installed position, intermediate limb portions for bearing upwardlyon the downwardly facing abutment surface, and an outer portionconnected to each intermediate limb portion for extending outwardly fromsaid abutment surface and curbing laterally arcuately outwardly andoutwardly toward a lower portion adapted to bear on a bearing surface,and wherein in said installed position there is a reaction between theintermediate limb portions and the downwardly facing abutment surfaceflexing the intermediate limb portions resiliently downwardly; whereineach lower portion inclines longitudinally with respect to said verticalplane; and wherein each lower portion inclines longitudinally outwardlyin a direction laterally inwardly.
 2. A device according to claim 1wherein the lower portion of each side of said clip is adapted to bearon said bearing surface at a region thereof which is offset laterallyinwardly from a centre of curvature of said outer portion of each sideof said clip.
 3. A device according to claim 1 wherein the inner portionof the clip comprises an upwardly bowed portion that is adjacent theabutment surface in the installed position.
 4. A device according toclaim 3 wherein in a free, non-installed condition of the clip, saidupwardly bowed portion defines a positive angle with a lower bearingsurface of said lower portion.
 5. A device according to claim 1including a wall member connected to the shoulder member longitudinallyoutwardly from each lower portion for limiting outward movement thereof.6. A device according to claim 1 wherein each lower portion continues inan upward and inward extension that extends above an upper edge of theshoulder member in the installed position.